How many letters does the top answer for “a protuberance on a bone especially for attachment of a muscle or ligament” have?

The most common answer is tubercle (8 letters).

Crossword clue: a protuberance on a bone especially for attachment of a muscle or ligament

2 answers found in Letterora's clue database (Wikidata facts, Open Trivia DB, WordNet and Webster definitions — all licensed sources).

tubercle 8 letters wn-def

a protuberance on a bone especially for attachment of a muscle or ligament

tuberosity 10 letters wn-def

a protuberance on a bone especially for attachment of a muscle or ligament